The objective is the theoretical and empirical analysis of the choices made by youth among major categories of household and market activities with an emphasis on family formation and fertility. Although the precise forms of the relationships may differ between males and females because of cultural and biological factors, members of each sex are viewed as making basically interdependent decisions on family formation, fertility, education, and market work as they attempt to adjust to social and economic conditions in an optimal fashion. The main emphasis will be on the effects of tastes and the appropriate relative prices and wealth position on these decisions, where prices and wealth are interpreted in a family, rather than an individual context; the interrelationship between family of orientation and family of procreation is a central theme of the analysis. Individuals in the family formation part of the life cycle are particularly interesting; major market and social investments which yield returns over the lifetime are most usefully made during these early years when individuals find it most difficult to borrow, because typically their only collateral would be future earnings. We explicitly consider the effect of this capital constraint on education, labor supply, and the optimal number and spacing of children. The behavioral relationships for family formation, fertility, education, and market work will then be estimated using disaggregated data from the National Longitudinal Surveys, a five year panel survey on several age-sex groups, of which the surveys of male and females age 14- 24 will be particularly useful. The estimation techniques will principally be ordinary least squares and 2-stage and 3-stage least squares.